Document Outlining Cullinan Cutting Smashes Pre-Sale Estimate

London—The document outlining the handling, cleaving and cutting of the world’s largest gem-quality rough diamond was a hit at auction.

At Bonhams’ London Jewels sale on Tuesday, the historic agreement that facilitated the cutting of the 3,106-carat Cullinan diamond garnered $27,720 (including the buyer’s premium), going for well above its pre-sale estimate of $2,600 to $3,900.

The Cullinan rough diamond was discovered near Pretoria, South Africa, in 1905. So large it was believed to be a piece of rock crystal instead of a diamond, the rough was named after Thomas Cullinan, chairman of the mine where it was found.

The Bonham’s lot included the original manuscript for the ‘Agreement for the Inspection of the Cullinan Diamond’ between the representatives of King Edward VII and London diamond brokers M.J. Levy & Nephews, dated Jan. 29, 1908.

The document appointed M.J. Levy and Nephews as “inspectors” of the Cullinan and outlined the parameters and guidelines of how it had to be handled, as well as the duties of each party.

It brokered the handling and cutting of the Cullinan by the Asscher Company to create the nine principal Cullinan Diamonds, Bonhams said, which make up part of the collection of the Crown Jewels and the collection of Her Majesty The Queen.

In addition to the document, the auction lot also included a paste replica of the rough Cullinan diamond and two replica sets of the nine principal diamonds, as well as a pamphlet of 15 printed images documenting the various states of the Cullinan during the cutting process.

Highlighting the rest of Tuesday’s London Jewels auction, a 17.43-carat Kashmir sapphire and old brilliant-cut diamond ring from the property of a European noble family was the top lot, garnering about $940,500, nearly double its pre-sale estimate.

This was followed by a transformable necklace by Spanish jeweler Grassy, circa 1935, featuring a 34.59-carat sapphire and approximately 40 carats of diamond accents. It sold for approximately $374,000.

The No. 3 highest-grossing lot was a 9.07-carat step-cut diamond ring that went for about $325,200; at No. 4 was a pair of old brilliant-cut diamond earrings, weighing 11.27 and 10.61 carats, that garnered about $211,400; and at No. 5 was a Cartier “Toi et Moi” crossover ring, set with a 4.35-carat step-cut fancy intense yellow diamond and a 4.47-carat step-cut diamond, which went for $187,100.